Table 1.

The number of wildfires, total burned area (ha), and fire season length (IQR, in days), by ecoregion (ordered by percent human-caused fires) and within the coterminous United States from 1992 to 2012

EcoregionNo. of firesHuman caused (%)Area burned (ha)Human caused (%)Length (IQR, days)Human expansion (%)
HumanLightHumanLightHumanLight
MC87,2742,855972,143,282253,210898545189
NF61,6732,57496302,56182,721795179N/A
ETF815,49944,859953,827,045829,2938216766253
MWCF14,5869259419,25127,291416752129
GP134,94417,586883,992,5572,564,9556114847315
SSH7,5042,16778340,873254,418575541134
TWF4,8321,91772357,150350,477509852188
NAD55,42252,044522,394,6778,880,691219240230
NFM76,73594,017451,895,6225,731,733257536208
TS13,60726,50234754,3931,152,064408539218
CONUS1,272,076245,4468416,027,41220,126,8524415446335
  • CONUS, Coterminous United States; ETF, Eastern Temperate Forests; GP, Great Plains; MC, Mediterranean California; MWCF, Marine West Coast Forests; NAD, North American Desert; NF, Northern Forests; NFM, Northwest Forested Mountains; SSH, Southern Semiarid Highlands; TWF, Tropical Wet Forests; TS, Temperate Sierras.